* Added documentation to AbstractResultBuilder, ConstResult and EmptyResult,
* Slightly improved readability of AbstractResultBuilder implementation.
* Added documentation to ExceptionFactory,
* Slightly improved readability of ExceptionFactory implementation.
* Improved documentation of GameFactory.
* Added documentation to helpers.
* Added documentation to InnerNullFactory.
* Documentation and readability improvement in several classes,
* Added explicit modifier where it makes sense.